<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form class="form-signin"  th:action="@{/book/login}" method="post">
    <!-- 取值替换原来默认的值-->

    <h1 class="h3 mb-3 font-weight-normal">Please sign in</h1>
    <p style="color:red" th:text="${msg}"  th:if="${not #strings.isEmpty(msg)}"></p>
    <label class="sr-only" >Username</label>
    <input type="text" name="username" class="form-control" placeholder="Username"
           required="" autofocus="">
    <label class="sr-only" >Password</label>
    <input type="password" name="password" class="form-control" placeholder="Password"
           required="">
    <div class="checkbox mb-3">
        <label>
            <input type="checkbox" value="remember-me"/> Remember me
        </label>
    </div>
    <button class="btn btn-lg btn-primary btn-block" type="submit" >Sign in</button>
    <p class="mt-5 mb-3 text-muted">© 2019-2020</p>
</form>
</body>
</html>